For more than two years, as his health deteriorated, Ethiopian opposition leader Bekele Gerba was locked up in a notorious high-security prison on the outskirts of Addis Ababa, accused of “terrorism” for leading anti-government protests.

This week, the authorities needed him for a different reason. He and many other opposition activists were invited to a palace to dine with Ethiopia’s new Prime Minister. The country needs “strong competing parties, more than ever before,” Prime Minister Abiy Ahmed told them.

It was the latest sign of a new era in Africa’s second-most populous country. While it remains dominated by an authoritarian government that has jailed hundreds in a state of emergency, there are hints of democratic reforms that could loosen the controls and allow greater political freedoms.

The new 41-year-old Prime Minister, Mr. Abiy, is the youngest head of government in Africa. In the two weeks since his inauguration, he has launched a charm offensive in an effort to defuse tensions: touring the country, freeing some prisoners, visiting the main regions where protests have erupted, restoring internet access in the restive Oromiya region and shutting down one of the most infamous prisons where dissidents were jailed and tortured.